ViiV Healthcare has reported positive results from the Phase III BRIGHTE clinical trial of fostemsavir evaluated for heavily treatment-experienced (HTE) patients with HIV-1 infection.

Fostemsavir is a HIV-1 attachment inhibitor being developed to bind to gp120 for preventing viral attachment to CD4.

Subjects given fostemsavir in combination with a failing regimen were observed to achieve a greater decrease in HIV-1 viral load after one week of treatment when compared to placebo.

Following the treatment, all patients were administered with fostemsavir and an optimised background regimen, which demonstrated virologic suppression in 54% of participants at 24 weeks.

The randomised and non-randomised Phase III trial assessed the safety and efficacy of fostemsavir in 371 patients with documented resistance, intolerability and/or contraindication to all antiretroviral (ARV) agents in a minimum of four out of the six available ARV classes.

“Patients who participated in this study had very limited treatment options left upon entry into the study.”

ViiV Healthcare chief scientific and medical officer John Pottage said: “Patients who participated in this study were failing their current antiretroviral regimens and had very limited treatment options left upon entry into the study, and the addition of fostemsavir to their failing regimen resulted in meaningful reductions in viral load at one week.”

BRIGHTE’s primary endpoint was mean change in log10 HIV-1 RNA between day one and day eight for the randomised arm, while the key secondary endpoints included durability of response at weeks 24, 48 and 96, safety and emergence of viral resistance.

The results revealed at least one adverse event in majority of patients treated with fostemsavir and 17 deaths associated with progression of the disease by the database lock at week 24.